Drinking Even Before Awareness of Pregnancy Harms Placental Health

Updated on October 4, 2018

Drinking is on the rise in the United Kingdom (UK) among women of reproductive age, according to a recent study. About half the women in UK of reproductive age claim to drink during the week and roughly 20% report binge drinking. The link between a pregnant woman’s drinking and fetal alcohol syndrome (FAS) is clearly established but 30% to 60% of all pregnant women in the world still consume alcohol while pregnant. A British research team devised a study to determine exactly how alcohol consumption becomes FAS.The researchers, led by Sylvia Lui of the Maternal and Fetal Health Research Center in Manchester, England, used mice in their study of the effects of alcohol on pregnancy.

For the study, alcohol consumption was measured in three categories:

Heavy drinking: The human equivalent of four to six drinks a day

Moderate drinking: Two to three drinks a day

Low drinking: Zero to one drink a day

The researchers discovered that heavy to moderate drinking during the first trimester inhibits cellular growth in the placenta. The health of the placenta promotes the health of the baby developing within it. When placental health is jeopardized in the beginning of the pregnancy, it likely affects the health of the entire pregnancy.

Low levels of drinking had no effect on the placenta’s cellular health but it is wise to remember the study was done on mice, not humans. Even low-level alcohol consumption may impair the health of the human placenta.

A second finding of the study involves the amino acid, taurine. Taurine passes from the mother’s bloodstream, through the placenta, and into the developing fetus. Amino acids, including taurine, are building blocks for proteins and are vital to healthy development of fetal brain and body development.

When a woman drinks in the moderate to heavy ranges during pregnancy, taurine doesn’t pass as freely from the mother to the child. Restricted access to taurine may explain the precise mechanisms that become the physical and behavioral impairments characteristic of FAS.

Both these findings affect the first trimester of pregnancy, with effects that likely carry through to the remainder of the pregnancy. This finding emphasizes the importance of alcohol abstinence in the earliest stages of pregnancy.

Most women, however, don’t suspect they are pregnant until a few weeks after conception occurs. The Lui study suggests women who plan to become pregnant should end alcohol consumption before trying to get pregnant. Those who get pregnant accidentally are advised to stop drinking the moment pregnancy is suspected.